Comparisons of mammalian Giardia duodenalis assemblages based on the β-giardin, glutamate dehydrogenase and triose phosphate isomerase genes

Department of Clinical Sciences, 300 West Drake Road, Fort Collins, CO 80525, United States. Electronic address: .
Veterinary Parasitology (Impact Factor: 2.46). 05/2012; 189(2-4):182-8. DOI: 10.1016/j.vetpar.2012.04.032
Source: PubMed


The objective of this study was to determine and compare the assemblages of Giardia duodenalis isolated from mammalian fecal samples using the β-giardin (bg), glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi) genes. A total of 202 samples, either submitted to the Veterinary Diagnostic Laboratory (Parasitology) at Colorado State University or part of ongoing research studies, were typed. A subset of 50 dog samples were also assessed by the tpi-D-specific primers. Of these, 183 were from dogs, 13 were from cats, two were from llamas, and one each was from a calf, an alpaca, a sheep, and a horse. The majority of the dogs (171 of 183 isolates) in this study were infected with only dog-adapted Assemblage C or D. The tpi-D-specific primers confirmed that 28 of the samples that typed as Assemblage D by the bg and gdh genes were also Assemblage D by the tpi-D-specific primers. Only 12 isolates were Assemblage A alone or Assemblage A and Assemblage C or D. Of the 13 cat isolates, seven were Assemblage F, two were Assemblage D, three were Assemblage A and 1 contained both Assemblages C and D. The calf isolate was Assemblage E (gdh, tpi) and the alpaca (bg, gdh), llamas (gdh), sheep (bg, gdh, tpi) and horse (tpi) isolates were all Assemblage A. When the assemblage could be determined for more than one gene, 91 of 117 dog isolates gave consistent results and 8 of 9 cat isolates gave consistent results.

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    • "Molecular characterization and phylogenetic analysis of G. duodenalis isolates from different hosts have revealed at least eight major genotypes Assemblage A, B, C, D, E, F, G and H (Scorza et al. 2012). However, cattle are susceptible with only two genotypes of G. duodenalis: the zoonotic genotype (Assemblage A), the livestock genotype (Assemblage E) (Thompson 2003). "
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    ABSTRACT: The aims of this study were to determine prevalence and genotype of Giardia duodenalis in feces of dairy cattle from the northern part and the northeastern part of Thailand. A total of 900 fecal samples were collected directly from rectum and examined by using zinc sulphate centrifugal flotation technique and polymerase chain reaction (PCR). The overall prevalence of G. duodenalis in dairy cows was 5.0 % (45/900) by zinc sulphate centrifugal flotation and 6.0 % (54/900) by PCR. Genotypes of G. duodenalis found in this study were Assemblage AI and E. The results indicated that dairy cattle may act as a potential risk of Giardia transmission among animals and humans (especially Assemblage AI).
    Full-text · Article · Sep 2015 · Acta Parasitologica
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    • "They are considered host-adapted genotypes and a species name, Giardia canis, was proposed to label them. As regards cats, in our study the host-adapted F genotype was not found; however, G. duodenalis infections sustained also by assemblages A, B, C, and D have been previously described in cats [40, 42]. In owned cats, we observed a high prevalence of G. duodenalis infection by assemblage A, whose possible zoonotic potential must not be underestimated [31]. "
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    ABSTRACT: Intestinal parasites of dogs and cats are cosmopolitan pathogens with zoonotic potential for humans. Our investigation considered their diffusion in dogs and cats from northern Italy areas, specifically the metropolitan area of Milan and two micropolitan areas of neighboring provinces. It included the study of the level of awareness in pet owners of the zoonotic potential from these parasites. A total of 409 fresh fecal samples were collected from household dogs and cats for copromicroscopic analysis and detection of Giardia duodenalis coproantigens. The assemblages of Giardia were also identified. A questionnaire about intestinal parasites biology and zoonotic potential was submitted to 185 pet owners. The overall prevalence of intestinal parasites resulted higher in cats (47.37%−60.42%) and dogs (57.41%−43.02%) from micropolitan areas than that from the metropolis of Milan (dogs: P = 28.16%; cats: P = 32.58 %). The zoonotic parasites infecting pets under investigation were T. canis and T. cati, T. vulpis, Ancylostomatidae, and G. duodenalis assemblage A. Only 49.19% of pet owners showed to be aware of the risks for human health from canine and feline intestinal parasites. Parasitological results in pets and awareness determination in their owners clearly highlight how the role of veterinarians is important in indicating correct and widespread behaviors to reduce risks of infection for pets and humans in urban areas.
    Full-text · Article · Apr 2014 · BioMed Research International
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    • "Cattle-derived G. duodenalis isolates were identified as assemblage E based on successful PCR and sequencing analysis, respectively at the gdh locus (n = 8) and at the bg locus (n = 4); however, all the DNA preparations used above were previously identified as assemblage B based on the tpi gene (Table 1). Similar findings were reported in an identification study of dog-derived G. duodenalis isolates, where an isolate was typed as assemblage AI based on the tpi gene while it was typed as assemblage D based on the gdh and bg genes [39]. It has also been observed that three out of five human-derived G. duodenalis isolates were identified as assemblage A at the18S rRNA locus and assemblage B at the gdh locus, while the remaining two were identified as assemblage B at the 18S rRNA locus and assemblage A at the gdh locus [40]. "
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    ABSTRACT: Giardia duodenalis is a common intestinal parasite that infects humans and many other mammals, mainly distributing in some areas with poor sanitation. The proportion of the human giardiasis burden attributable to G. duodenalis of animal origin differs in different geographical areas. In Mainland China, genetic data of the gdh and bg genes of G. duodenalis from animals are only limited in dogs and cats. The aim of the study was to provide information on the genetic characterizations of animal-derived G. duodenalis isolates (from rabbits, sheep and cattle) at both loci in Heilongjiang Province, Northeastern China, and to assess the potential for zoonotic transmission. 61 G. duodenalis isolates from animal feces (dairy and beef cattle, sheep and rabbits) in Heilongjiang Province were characterized at the gdh and bg loci in the present study. The gdh and bg gene sequences of sheep-derived G. duodenalis assemblage AI, and the gdh sequences of rabbit-derived G. duodenalis assemblage B had 100% similarity with those from humans, respectively. Novel subtypes of G. duodenalis were identified, with one and seven subtypes for assemblages A and E at the gdh locus, and two and three subtypes for assemblages B and E at the bg locus, respectively. Three pairs of the same bg sequences of assemblage E were observed in sheep and cattle. This is the first description of genetic characterizations of the gdh and bg genes of G. duodenalis from rabbits, sheep and cattle in Mainland China. Homology analysis of assemblages AI and B implied the possibility of zoonotic transmission. The novel subtypes of assemblages of G. duodenalis may represent the endemic genetic characteristics of G. duodenalis in Heilongjiang Province, China.
    Full-text · Article · Apr 2014 · PLoS ONE
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